粉体工学会誌
Online ISSN : 1883-7239
Print ISSN : 0386-6157
ISSN-L : 0386-6157
49 巻, 3 号
Special Issue of 47th Summer Symposium
選択された号の論文の11件中1~11を表示しています
  • 平林 靖, 中平 翔, 山中 真也, 藤本 敏行, 空閑 良壽
    2011 年 49 巻 3 号 p. 164-170
    発行日: 2012/03/10
    公開日: 2012/03/22
    ジャーナル フリー
    Functional plywood can produce constant heat by applying a voltage to the conductive bonding layer between wood sheets. Herein functional plywood was prepared by filling various microsized graphite particles (3.3-52.5μm in diameter) and nanosized carbon black (CB ; 29 nm) into a phenolic resin. To investigate the electrical conductivity, the resulting composite resin was coated onto a commercial glass slide. The effects of particle size, mass fraction of the conductive fillers (graphite and CB), and the weight ratio of graphite to the fillers (φ = graphite / (graphite + CB)) on the conductive properties of the composite resin, particularly the specific resistance and its variation coefficient, were estimated. A composite resin, which included at least 30 mass% of filler, yielded a relatively low variation coefficient for the specific resistance. Additionally, the composition of the resin had superior conductivity when the weight ratio was 55-66 mass% and the graphite particles were 22.9μm or less in diameter.
    The above experiment indicated heating plywood was produced. Consequently, its surface temperature was measured. With respect to particle size, the standard deviation in the surface temperature of the plywood corresponded to that of the conductive properties on the glass slide. Hence, the method proposed herein using a glass slide is suitable for conductive characterization to determine the appropriate conditions to prepare heating plywood.
  • 木俣 光正, 長谷川 政裕
    2012 年 49 巻 3 号 p. 171-176
    発行日: 2012/03/10
    公開日: 2012/03/22
    ジャーナル フリー
    The hydrogen production was carried out by the agitation of dispersed waste aluminum fine powders in water. A magnetic stirrer was used for agitation of the mixtur in a triangle flask. The waste fine powders from the arc spraying and the plasma spraying were used as aluminum source. In the experiment, reaction temperature, number of revolutions and the size and shape of magnetic stirrer bars were changed. The shape of the waste aluminum fine powders was observed by a scanning electron microscope. Crystal structure was investigated by powdery X-ray diffraction. As a result, the hydrogen amount of production changed by different waste aluminum fine powders at the same agitation condition. It was found that the powder after the reaction with the water formed larger size aggregates and generated a lot of aluminum hydroxide. In addition, agitation speed and the size of magnetic stirrer bars had a large influence on the production of hydrogen.
  • 浅井 一輝, 長縄 佳祐, 森 隆昌, 椿 淳一郎
    2012 年 49 巻 3 号 p. 177-183
    発行日: 2012/03/10
    公開日: 2012/03/22
    ジャーナル フリー
    Particle assembling state in suspensions prepared by different ways was numerically characterized by direct observation method. The aqueous suspensions of alumina powder were prepared by ultrasonication and ball milling. The particle assembling state was characterized by settling test and particle size measurement in addition to the direct observation. From the comparison, the particle images in a suspension getting by the direct observation method can much more distinguish coarse aggregates from primary particles than the other ways. And the black and whiteness of the particle images were classified into 256 steps. The mean values and standard deviations of the black and whiteness distributions were calculated. The variation coefficient determined by the standard deviation over the mean value can show the existence of coarse aggregates that were not ground or re-aggregated.
  • 森部 久仁一, 永井 愛子, 萩原 由実, Limwikrant Waree, 東 顕二郎, 山本 恵司
    2012 年 49 巻 3 号 p. 184-190
    発行日: 2012/03/10
    公開日: 2012/03/22
    ジャーナル フリー
    Effect of dicarboxylic acids : malonic acid (MA), succinic acid (SUA), and glutaric acid (GA), on the preferential cocrystal formation with carbamazepine (CBZ) was investigated. Stoichiometries of CBZ / MA, CBZ / SUA and CBZ / GA cocrystals formed were 2 / 1, 2 / 1 and 1 / 1. When CBZ / SUA ground mixture (GM) was coground with MA, CBZ / SUA cocrystal still remained, i.e., no exchange reaction occurred. On the other hand, exchange reaction occurred when CBZ / MA GM was coground with SUA. CBZ / SUA cocrystal was formed by ternary cogrinding of CBZ, MA and SUA. In CBZ, MA and GA system, preferential cocrystal formation was observed for CBZ / GA. The results of cryogenic cogrinding suggested that preferential CBZ / GA cocrystal formation was due to the stable and rapid crystallization. Preferential CBZ /GA cocrystal formation was assumed when CBZ, SUA and GA ternary cogrinding was performed. Structure and stability of cocrystal, mechanism of cocrystal formation and grinding energy affected the preferential cocrystal former exchange reactions.
  • 竹内 寛久, 仲村 英也, 綿野 哲
    2012 年 49 巻 3 号 p. 191-200
    発行日: 2012/03/10
    公開日: 2012/03/22
    ジャーナル フリー
    Numerical modeling of individual particle motion and fluid flow in an impact pulverizer was conducted using a Computational Fluid Dynamics (CFD) - Discrete Phase Model (DPM) coupling model. The impact pulverizer consists of high-speed rotating hammers and a static concavo-convex stator. Influences of the rotor geometries on particle impacts against stator walls were investigated. It was found that particles in the impact pulverizer were accelerated by the fluid drag force caused by the rotating hammers but not by the impact force from the hammers, resulting in impacts against walls of the static stator. Velocities and frequencies of the impacts between particles and walls of the static stator were analyzed under various number of hammers and clearances. As the number of hammers increased, the velocity and frequency increased because velocity of the fluid in circumference of the grinding chamber increased. The number of particle impacts against walls of the static stator decreased with an increase in the clearance. The impact energy which was calculated from the velocity and frequency of the particle impacts has the similar tendency with the experimental ones.
  • 綱澤 有輝, 所 千晴, 大和田 秀二, 酒井 幹夫, 村上 進亮
    2012 年 49 巻 3 号 p. 201-209
    発行日: 2012/03/10
    公開日: 2012/03/22
    ジャーナル フリー
    The mechanism of part detachment and board breakage process in a drum-typed impact mill to recover valuable metals by removing components from printed circuit boards (PCBs) was investigated. Experimental results using test PCBs showed that parts detachment was enhanced by the increase of input number of PCBs in the mill and board breakage was enhanced by the increase of rotational speed of the agitator. DEM simulation results using spherical particles model showed that board breakage was achieved by the collision of boards with drum wall and agitator, and part detachment was achieved by the interaction between PCBs.
    To simulate part detachment and board breakage process more briefly, particle-based rigid body model, in which model PCB geometry was constructed consisting of bonded particulates, was included to DEM simulation. Simulation results showed that board breakage was obtained from the impact of boards with the drum wall and part detachment was obtained from the collision of the boards with each other. These simulation results were successfully corresponded to experimental observations.
技術資料
解説
  • 齋藤 文良
    2012 年 49 巻 3 号 p. 226-231
    発行日: 2012/03/10
    公開日: 2015/08/05
    ジャーナル 認証あり
    Grinding makes surface area of solid increase with accelerating mechanical activation. This induces mechano-chemical (MC) reaction in the solids at certain level of energy stored in the solid, and its reaction yield improves as the grinding progresses. There have been a lot of investigations on the MC reaction in various materials, but its practical applications have rarely been materialized. The author's group has attempted the highly utilization of grinding operation, aiming its engineering application in terms of recycling, waste treatment and clean technology. Some of them have been introduced in this paper.
  • 空閑 良壽
    2012 年 49 巻 3 号 p. 232-241
    発行日: 2012/03/10
    公開日: 2015/08/05
    ジャーナル 認証あり
    The aim of this study on grinding is not only to investigate particle size change during the grinding, but also to improve the functional properties of the ground products. Because highly crystalline natural graphite has many types of functional properties, such as a high electrical conductivity, absorption of guest molecules, and excellent lubricant properties due to π-electrons between the lamellar crystal structures, the author has chosen to study the grinding of natural graphite particles. The author aims to investigate the effect of various grinding methods on the functional properties of the products.
    The author begins this study by investigating experimentally the effects of a wide variety of gaseous and alcoholic vapors present during milling on the flakiness of ground natural graphite particles and the electrical conductivity of films composed of these products. The author then proceeds to evaluate these particles in negative electrode materials for lithium ion batteries, and in hydrogen storage materials. A new grinding method for both dry and wet processes, which uses graphite intercalation compounds and their exfoliated products to obtain flaky graphite particles as the raw materials mentioned above, has been also proposed.
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